North Yorkshire Police has said its officers will use checkpoints to stop vehicles and ask drivers if their journey is essential while the UK remains on lockdown because of coronavirus.
The checkpoints are due to be rolled out from today onwards and will be unannounced, meaning they could appear anywhere and at any time.
The force said officers will ask motorists where they are going, why they are going there, and reminding them of the Government's message to "stay at home, protect the NHS and save lives".
Assistant Chief Constable Mike Walker, said: "The new and significant restrictions announced by the Prime Minister on Monday evening spell out very clearly what each and every one of us must do to save lives. The message is clear and the warning stark. Stay at home, save lives.
"Alongside the new restrictions, the Government announced new powers to enforce them. I know the vast majority of people will follow the restrictions without question, as they have done so already.
"And as the legislation comes into force, the roadside checks will help us to reinforce the messaging. So we ask people not to make non-essential journeys, and to understand the definition of essential. We sincerely hope that we won’t have to resort to enforcement action, but if people do not comply, we will."
Under the extraordinary measure, people are only permitted to leave their homes to buy basic necessities such as food and medicine "as infrequently as possible", take one form of exercise in public a day and access medical help or provide care to a vulnerable person.
Those designated as key workers - including NHS staff, teachers and postal, transport and utility workers - are also permitted to travel to and from work and to take their children to school using necessary modes of transport.
Police have been granted the power to impose fines on people found contravening the new rules and disperse group gatherings.
The Government has committed to reviewing the lockdown measures in three weeks and relaxing them if possible.
Meanwhile, the number of confirmed coronavirus cases in the UK has passed 9,500. The death toll nationwide now stands at 463, three weeks after the first coronavirus-related death in the UK was reported on March 5.